Question

In which chemical equation is the number of atoms in the reactants the same as the number of atoms in the products?
1:Li2CO3 → LiO + CO2
2:Zn + 2HCl → H2 + ZnCl2
3:CO2 + H2O → CH2OH + O2
4:CH4 + O2 → CO2 + 2H2O

Answer 1

I’m not very sure but I think it’s 4

Answer 2

The answer is the second one